It is known that peanut butter consists of a mixture of solid nut particles and liquid peanut oil which is generally made by roasting and blanching raw peanut kernels and then grinding hem. The grinding operation breaks the cellular structure of the peanut kernels and liberates oil in which the comminuted nut particles are suspended to form a product having a pasty and spreadable consistency. This product is generally called the peanut "paste". A stabilizer is usually added to the peanut paste in making peanut butter to prevent oil separation, and optionally other ingredients are added such as an emulsifier, a sweetener and salt.
Peanut butter has high nutritional value as a good source of protein. The protein content of a typical peanut butter is around 29%. Unfortunately, the high oil content of peanut butter (typically around 50%) also causes it to be very high in calories. Hence, the nutritional appeal of peanut butter is partly offset by its high caloric content. Therefore, it would be desirable to have a peanut butter that is still high in protein but that contains a reduced amount of oil.
There have been various attempts in the art to make improved peanut butters. For example, British Patent Application 2,007,961A of Sharma, published May 31, 1979, discloses a low calorie peanut spread comprising a dispersion of finely divided peanut meat in a continuous oil phase. The spread has a reduced oil content of 20-35% and an oil to peanut protein ratio of 1:2 to 4:3.
Additionally, U.S. Pat. No. 3,865,939 of Jandacek, issued Feb. 11, 1975, discloses a hypercholesterolemic oil suitable for use in peanut butter comprising a liquid glyceride base oil, 2.0-6.9% of a plant sterol, and a solubilizing agent for the sterol. The base oil can comprise triglycerides in which one or more short chain fatty acids, such as acetic or propanoic acid, replace in part the long chain fatty acids present in natural triglyceride oils.
Several patents disclose methods for making low-fat nuts such as peanuts. For example, U.S. Pat. No. 4,329,375 of Holloway et al., issued May 11, 982, discloses a process in which the nuts are initially roasted to develop a roasted flavor and color prior to pressing them to remove only a limited amount of the oil. After the initial roasting, the nuts are hydrated and equilibrated for a period of time to obtain a uniform moisture content within the range of from about 4% to 8%. The hydrated nuts are then pressed to remove from about 20% to about 55% of the oil and then hydrated to a moisture content sufficient to cause the nuts to regain approximately their normal shape prior to a final roasting to fully develop the flavor and color of the nuts.
U.S. Pat. No. 4,049,833 of Gannis et al., issued Sept. 20, 1977, discloses a process in which partially defatted nuts are contacted with a glycerol-containing solution until at least a portion of the solution is absorbed by the nuts and the nuts have regained their original size and shape. The nuts are then removed from contact with the solution and roasted to provide partially defatted nuts having improved flavor and texture.
Medium chain triglycerides (MCT's) are known to the art for use as a substitute for typical triglyceride fats. MCT's are triglycerides esterified with saturated C.sub.6 to C.sub.12 fatty acids. These medium chain triglycerides are metabolized differently from long chain triglycerides by the body because they are more water-soluble. In addition, they hydrolyze rapidly and are absorbed via the portal vein, providing a source of quick energy. A discussion of medium chain triglycerides is provided by Bach et al., "Medium-Chain Triglycerides: an Update," The American Journal of Clinical Nutrition 36, Nov. 1982, pp. 950-962.
There is no mention in these references of a way to make a peanut butter that is reduced in calories through a reduction in the amount of peanut oil and total oil, while at the same time maintaining the desired consistency of the peanut butter.
Therefore, it is an object of the present invention to provide a peanut butter that is reduced in calories.
It is another object of the present invention to provide a reduced calorie peanut butter in which the calorie reduction is achieved by the replacement of at least a portion of the peanut oil with triglycerides containing medium chain fatty acids.
It is a further object of the present invention to make a reduced calorie peanut butter that has a lower level of total oil, while at the same time having an excellent consistency.
These and other objects of the invention will become evident from the disclosure herein.
All parts, percentages and ratios used herein are by weight unless otherwise indicated.